These studies are designed to develop improved methods for detecting and treating malignancies. Our group performs preclinical evaluation of antibodies that appear to be promising after initial screening by various laboratories at the National Cancer Institute and develops these antibodies for clinical application. The clinical trials evaluating their pharmacokinetics and dosimetry are performed by our group. A collaborative radioimmunotherapy trial with Dr. Waldmann (PI), in which we used humanized anti-tac monoclonal antibody, is ongoing. A collaborative radioimmunotherapy trial with bone marrow support is ongoing with NCI(Dr, Bishop and Pastan). Various protocols using [F-18] FDG in PET and [O-15] water for tumor detection, followup, and blood flow measurements are ongoing with NCI surgery Branch (Dr. Libutti). There are 4 ongoing collaborative studies evaluating fluorodeoxyglucose-PET for assessing tumor response to treatment (Dr. Swain, Dr. Mackall, Dr. Sausville and Dr. Wilson). We have evaluated the use of fluorodeoxyglucose-PET in assesing sites of viral replication in patients with HIV (Dr. Brust). We have utilized FDG-PET to evaluate sites of metabolic activity in patients with systemic lupus erythematosus. We have perfomed preclinical studies evaluating pretargeting of antibodies for tumor therapy and have demonstrated therapeutic responses with Y-90 and Bi-213 in animal tumor models. Two antibody -strepavidin conjugates have been evaluated preclinically and paper have been accepted for publication. We are evaluating a third anti-mesothelin-strepavidin conjugated antibody.